Passionfruit Plant Dropping Leaves

Question

I recently planted a planted a passionfruit plant (grafted Nellie Kelly). It grew fast and seemed to be going well. A few days ago, I noticed that one of the leaves had fallen off. As the plant still looked healthy and it was just one leaf, I assumed it must have been wind or something falling on the plant. However, soon after that, the top of the plant disappeared and then yet another leaf fell off. I'm worried that the plant is dying but it still looks healthy to me. Any suggestions?

Notes

• The plant still looks healthy, the leaves are not yellowing.
• My suspicion is that it is the cold weather (Temperatures as low as 3-4˚C (37-39˚F))
• Location: Canberra, Australia (going into spring)
• Plant was transplanted about 4 weeks ago.
• Plant is watered every second say and is mulched.

Photos (click to enlarge)

This photo shows a point on the plant where a leaf has broken off:

The photo shows the top of the plant, with the tip missing:

This photo shows one of the leaves that has fallen off:

This photo shows the whole plant (now):

This photo shows the whole plant (one week ago, before the leaf drop):

Any suggestions of what to do or comments on what is happening would be appreciated. If I have left out any vital information feel free to comment and I will add it.

Answer 1

This time of year the Passiflora's tend to drop their leaves. There are also gulf fritillary caterpillars that will do a lot of damage to the plant. (you will notice medium sized orange butterflies) This is their "host" plant. To me, the plant looks good for October, it may just have been going dormant as they sometimes do. Mine stay growing through the winter but look terrible until spring.